Defects of Neurotransmission in Ischemia and Reperfusion

缺血和再灌注中神经传递的缺陷

• 批准号: 7197100
• 负责人: Alexander A Mongin
• 金额: $ 19.47万
• 依托单位: ALBANY MEDICAL COLLEGE
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-02-05 至 2008-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7197100
• 关键词: 7-nitroindazole; ATP phosphohydrolase; Acetylcysteine; Affect; Antioxidants; Arts; Attention; Biological Preservation; Blood flow; Brain; Cardiovascular system; Cell Death; Cell physiology; Cessation of life; Chemistry; Chimeric Proteins; Communication; Cysteine; Data; Defect; Disruption; Docking; Environment; Equipment; Ethylmaleimide; Freezing; Functional disorder; Genes; Glutamate Receptor; Hour; Impairment; Interdisciplinary Study; Interruption; Intervention; Ischemia; Ischemic Penumbra; Knowledge; Laboratories; Lesion; Link; Literature; Measurement; Measures; Medical; Metabolism; Methods; Modeling; Modification; Molecular; Molecular Conformation; Monitor; Motor Cortex; N-ethylmaleimide-sensitive protein; Neurons; Neuropharmacology; Neurosciences; Nitric Oxide; Nitrosation; Pathologic Processes; Pathology; Patients; Phosphorylation; Physiological reperfusion; Post-Translational Protein Processing; Preparation; Proteins; Proteomics; Rattus; Reactive Nitrogen Species; Reagent; Recording of previous events; Reducing Agents; Rehabilitation therapy; Reperfusion Therapy; Reporting; Research; Research Personnel; Running; SNAP receptor; Science; Stroke; Sulfhydryl Compounds; Synapses; Synapsins; Synaptic Transmission; Synaptic Vesicles; Synaptosomes; Tamoxifen; Testing; Tissues; Transient Ischemic Attack; Vesicle; Work; base; brain tissue; college; day; expectation; experience; in vivo; inhibitor/antagonist; knockout animal; neurotransmission; neurotransmitter release; oxidation; postsynaptic; presynaptic; prevent; programs; protein function; response; size; tissue preparation

DESCRIPTION (provided by applicant): Stroke is a pathological reduction in blood flow which causes irreversible damage of brain tissue, long-term disruptions of brain functions, and frequently patient death. The major focus of ischemia research is on the mechanisms of cell death and the search for pharmacological approaches to salvage vulnerable neural cells. Substantially less attention is paid to long-term impairment of neural cell function that is not associated with cell death. Existing literature suggest, nonetheless, that even relatively mild ischemia causes long-lasting suppression of synaptic communication. For unknown reasons, only presynaptic release is affected, while postsynaptic responses remain preserved. In the current study we hypothesize that suppression of synaptic transmission occurs due to nitrosation of cysteine residues in N-ethylmaleimide sensitive fusion protein (NSF) by nitric oxide (NO) and NO-related reactive nitrogen species. The NSF protein is a trimeric ATPase which is crucial for continuous synaptic vesicle docking/fusion. Modification of a critical cysteine residues in the NSF by N-ethylmaleimide causes irreversible inhibition of vesicle docking and fusion. Similarly, NOdependent modification of NSF thiols may cause long-term inhibition of vesicular neurotransmitter release. To test our hypothesis we propose the following specific aims. (1) We will test for the increased modification of thiols in the ischemic tissue up to 24 hours after ischemia and will further demonstrate thiol modification in the NSF protein immunoprecipitated from the ischemic brain. (2) Using synaptosomal preparation we will test whether nitric oxide and related reactive nitrogen species modify NSF and via this mechanism inhibit vesicular neurotransmitter release. We will further attempt to reverse NSF nitrosation and defects in neurotransmitter release by applying thiol reducing agents. This project will clarify the molecular mechanisms of less understood long-term disruption of synaptic transmission in ischemia and may suggest additional approaches for patient treatment and rehabilitation after stroke and transient ischemic attacks.

描述(申请人提供)：中风是一种血液流动的病理性减少，导致脑组织不可逆转的损害，脑功能的长期中断，并经常导致患者死亡。缺血研究的主要焦点是细胞死亡的机制和寻找药物方法挽救脆弱的神经细胞。对与细胞死亡无关的神经细胞功能的长期损害的关注明显较少。然而，现有的文献表明，即使是相对轻微的缺血也会导致长期的突触交流抑制。由于未知的原因，只有突触前的释放受到影响，而突触后的反应保持不变。在目前的研究中，我们假设突触传递的抑制是由于N-乙基马来酰亚胺敏感融合蛋白(NSF)中的半胱氨酸残基被一氧化氮(NO)及其相关的活性氮物种亚硝化所致。NSF蛋白是一种三聚体ATPase，对突触小泡的持续对接/融合至关重要。N-乙基马来酰亚胺修饰NSF中的一个关键半胱氨酸残基会导致不可逆的囊泡对接和融合抑制。同样，NO依赖的NSF硫醇修饰可能导致囊泡神经递质释放的长期抑制。为了验证我们的假设，我们提出了以下具体目标。(1)我们将测试缺血后24小时缺血组织中硫醇的增加修饰，并将进一步证明从缺血脑中免疫沉淀的NSF蛋白中的硫醇修饰。(2)利用突触小体制备技术，检测一氧化氮及相关活性氮物质是否能改变NSF，并通过此机制抑制囊泡神经递质的释放。我们将进一步尝试通过应用硫醇还原剂来逆转NSF的亚硝化和神经递质释放缺陷。该项目将阐明缺血时突触传递长期中断的分子机制，并可能为中风和短暂性脑缺血发作后的患者治疗和康复提供更多的方法。